Subdural effusion: results after treatment with subdural-pleural shunts.

In an unselected material of 22 consecutive patients subdural effusion, which did not respond to repeated taps, was treated with subdural-pleural shunt operation using nonvalve silicone catheters. After a mean follow-up time of 3 years 4 months, 17 patients (77%) were mentally and 15 patients (69%) neurologically normal. The results are certainly not worse than results achieved with craniotomies and membranectomies. A shunt operation is more simple and less hazardous than membranectomy and we agree with the opinion that the latter is an obsolete procedure in the treatment of persistent subdural effusions.